#define _CRT_SECURE_NO_WARNINGS  1
#if 0

#include<iostream>
using namespace std;

int main()
{
	int i = 12;
	std::cout << "Hello world!";
	std::cout << "Hello world! Hello world!" << std::endl;
	std::cout << 12 << "Hello World!" << std::endl;

	return 0;
}



#include<iostream>

int main()
{
	std::cout << "Hello World!" << std::endl;

	return 0;
}


#include<iostream>
using namespace std;

namespace egghead
{
	int a = 1;
	int b = 2;
}

namespace lvleft
{
	int c = 3;
}

int main()
{

	std::cout << "Hello World!" << std::endl;
	cout << "Hello World!" << endl;
	cout << "Hello World" <<211212<<endl;
	
	int a = 11, b = 12, c = 13;
	int& a1 = egghead::a;
	int&& a3 = a1;

	cout << &a1 << endl;
	cout << &egghead::a << endl;
	cout << a3 << endl;



	return 0;
}
#endif // 0

#include<iostream>

using namespace std;

int main()
{
	cout << "Hello World!" << endl;
}
